Context:
We use data extension to store email content and we have an Amp script that runs for each email trigger.
Amp script contains couple of placeholder replacement logic and link tracking SSJS script.

Problem Statement:
SSJS code block in our script is to place redirectTo function around each link to track the links in an mail.
This is particularly giving problem, due to this SSJS code block , large sends are taking time to finish.

Sollutions Tried:
we tried optimizing the SSJS link tracking script, but it is not getting better.
Instead of SSJS script, we wraped our content around TreatAsContentArea(), but this has limitation for 300 unique links , and it is not working.
Sample script we have:
%%[
SET @Full_Email_Html = /*Here is the code that gets content from DE and run some replacements*/
SET @Full_Email_Html = TreatAsContent(@Full_Email_Html);
]%%
<script runat=server>
Platform.Load('core','1');
function TrackLinksHTML(f){
if(f.indexOf('@')==0){
f=Variable.GetValue(f)
}
var g=f.match(/<a.*?href=["'].*?["'].*?>/i);
var h=f.split(/<a.*?href=["'].*?["'].*?>/i);
for(var i=0;i<g.length;i++){
Variable.SetValue('@a',g[i].match(/href=["'].*?["']/i)[0].replace(/href=["'](.*?)["']/i,'$1'));
Variable.SetValue('@b',g[i].match(/<a.*?href/i)[0].replace(/<a(.*?)href/i,'$1'));
Variable.SetValue('@c',g[i].match(/href=["'].*?["'].*?>/i)[0].replace(/href=["'].*?["'](.*?)>/i,'$1'));
Variable.SetValue('@d',h[i]);
</script>
%%=v(@d)=%%
<a %%=v(@b)=%% href="%%=RedirectTo(@a)=%%" %%=v(@c)=%%>
<script runat=server>}Variable.SetValue('@e',h[i]);</script>
%%=v(@e)=%%
<script runat=server>}</script>
<script runat="server"> TrackLinksHTML("@Full_Email_Html"); </script>

Questions:
"optimizing SSJS" or "TreatAsContentArea" are out of scope for us.
Are there any other alternatives for link tracking?

We tried with content builder , but it could not be used for tigger send and user intiated emails(like through api).It's only useful for manual send